Video signal processing apparatus, video signal processing method, and video signal recording/reproduction apparatus

Abstract

A video signal processing apparatus, video signal recording/reproduction apparatus, and method therefor, perform arithmetic operations upon an input video signal and the input signal delayed by a predetermined amount of time. A memory stores the input signal for the predetermined amount of time in order to produce the delayed input video signal. A controller controls the memory to store the input video signal for the predetermined amount of time based on a main synchronization signal. A first synchronization signal is produced by separating a synchronizing signal from the input video signal. A second synchronization signal is generated based on the first synchronization signal. During operation, a switching unit supplies the first synchronization signal to the controller as the main synchronization signal until the second synchronization signal becomes synchronized with the first synchronization signal. Once the second synchronization signal becomes synchronized with the first synchronization signal, the switching unit supplies the second synchronization signal to the controller as the main synchronization signal. In this manner, jitter caused by noise or distortion in the first synchronization signal separated from the input video signal is eliminated by the switching to the second synchronization signal. The second synchronizing signal is not affected by noise or waveform distortion; and consequently, arithmetic operations in the correct time axis are performed.

What is claimed is: 
     
       1. A video signal processing apparatus, comprising: synchronizing signal separating means for separating a first synchronizing signal from a current input video signal;   synchronizing signal generating means for generating a second synchronizing signal; and   means for obtaining a delayed input video signal based on the first synchronizing signal until the second synchronizing signal becomes synchronized with the first synchronizing signal, and then on the second synchronizing signal.   
     
     
       2. A video signal processing apparatus according to claim 1, further comprising: arithmetic means for performing arithmetic operations between the current input video signal and the delayed input video signal.   
     
     
       3. A video signal processing apparatus, comprising: synchronizing signal separating means for separating a first synchronizing signal from an input video signal;   synchronizing signal generating means for generating a second synchronizing signal; and   selecting means for selecting and outputting one of the first synchronizing signal and the second synchronizing signal as a main synchronizing signal, the selecting means selecting and outputting the first synchronizing signal as the main synchronizing signal until the second synchronizing signal becomes synchronized with the first synchronizing signal, and then selecting and outputting the second synchronizing signal as the main synchronizing signal.   
     
     
       4. A video signal processing apparatus according to claim 3, wherein the synchronizing signal generating means generates the second synchronizing signal such that the second synchronizing signal has substantially a same cycle as the first synchronizing signal. 
     
     
       5. A video signal processing apparatus according to claim 3, further comprising: timer means for measuring a predetermined period, the predetermined period being an amount of time for the second synchronizing signal to become synchronized with the first synchronizing signal; and wherein   the selecting means selects and outputs the second synchronizing signal as soon as the timer means indicates expiration of the predetermined period.   
     
     
       6. A video signal processing apparatus according to claim 3, further comprising: detecting means for detecting whether the input video signal is a standard video signal; and wherein   the selecting means performs the selecting and outputting based on output of the detecting means.   
     
     
       7. A video signal processing apparatus according to claim 3, wherein the selecting means selects and outputs the first synchronizing signal as the main synchronizing signal when the detecting means detects a non-standard video signal. 
     
     
       8. A video signal processing apparatus, comprising: storage means for storing an input video signal for a predetermined length of time;   arithmetic means for performing arithmetic operations between the input video signal and an output of the storage means;   synchronizing signal separating means for separating a first synchronizing signal from the input video signal;   synchronizing signal generating means for generating a second synchronizing signal; and   control means for controlling the operation of said storage means based on the first synchronizing signal until the second synchronizing signal becomes synchronized with the first synchronizing signal, and then on the second synchronizing signal.   
     
     
       9. A video signal processing apparatus according to claim 8, further comprising: extracting means for extracting, from the input video signal, video signal information necessary for the arithmetic operations performed by the arithmetic means, and for supplying the video signal information to the storage means.   
     
     
       10. A video signal processing apparatus according to claim 3, further comprising: storage means for storing the input video signal for a predetermined length of time;   arithmetic means for performing arithmetic operations between the input video signal and an output of the storage means;   storage control means for controlling the storage means based on the main synchronization signal;   counter means for controlling the storage control means; and wherein   the synchronizing signal generating means generates the second synchronizing signal based on an output of the counter means.   
     
     
       11. A video signal processing apparatus according to claim 10, wherein the counter means is a vertical-direction counter circuit suitable for counting operations in vertical directions of a television screen, the synchronizing signal separating means is a vertical synchronizing signal separation circuit for separating a first vertical synchronizing signal from the video signal, the synchronizing signal generating means is a vertical synchronizing signal generating circuit for generating a second vertical synchronizing signal, and the selecting means selects and outputs one of the first vertical synchronizing signal and the second vertical synchronizing signal as the main synchronizing signal.   
     
     
       12. A video signal processing apparatus according to claim 10, wherein the counter means is a horizontal-direction counter circuit suitable for counting operations in horizontal directions of a television screen, the synchronizing signal separating means is a horizontal synchronizing signal separation circuit for separating a first horizontal synchronizing signal from the video signal, the synchronizing signal generating means is a horizontal synchronizing signal generating circuit for generating a second horizontal synchronizing signal, and the selecting means selects and outputs one of the first horizontal synchronizing signal and the second horizontal synchronizing signal as the main synchronizing signal.   
     
     
       13. A video signal processing apparatus according to claim 12, further comprising: a vertical-direction counter circuit suitable for counting operations in vertical directions of a television screen;   a vertical synchronizing signal separation circuit for separating a vertical synchronizing signal from the input video signal; and   a vertical-direction reset circuit for generating a pulse to reset said vertical-direction counter circuit based on the vertical synchronizing signal; and wherein   the storage control means controls the storage means based on both the main synchronizing signal and the vertical synchronizing signal.   
     
     
       14. A video signal processing apparatus according to claim 10, further comprising: extracting means for extracting, from the input video signal, video signal information necessary for the arithmetic operations performed by the arithmetic means, and for supplying the video signal information to the storage means.   
     
     
       15. A video signal processing apparatus according to claim 10, further comprising: resetting means for controlling the counter means based on the main synchronizing signal.   
     
     
       16. A video signal processing apparatus according to claim 15, wherein the counter means is a vertical-direction counter circuit suitable for counting operations in vertical directions of a television screen, the synchronizing signal separating means is a vertical synchronizing signal separation circuit for separating a first vertical synchronizing signal from the video signal, the synchronizing signal generating means is a vertical synchronizing signal generating circuit for generating a second vertical synchronizing signal, and the selecting means selects and outputs one of the first vertical synchronizing signal and the second vertical synchronizing signal as the main synchronizing signal.   
     
     
       17. A video signal processing apparatus according to claim 15, wherein the counter means is a horizontal-direction counter circuit suitable for counting operations in horizontal directions of a television screen, the synchronizing signal separating means is a horizontal synchronizing signal separation circuit for separating a first horizontal synchronizing signal from the video signal, the synchronizing signal generating means is a horizontal synchronizing signal generating circuit for generating a second horizontal synchronizing signal, and the selecting means selects and outputs one of the first horizontal synchronizing signal and the second horizontal synchronizing signal as the main synchronizing signal.   
     
     
       18. A video signal processing apparatus according to claim 17, further comprising: a vertical-direction counter circuit suitable for counting operations in vertical directions of a television screen;   a vertical synchronizing signal separation circuit for separating a vertical synchronizing signal from the input video signal; and   a vertical-direction reset circuit for generating a pulse to reset said vertical-direction counter circuit based on the vertical synchronizing signal; and wherein   the storage control means controls the storage means based on both the main synchronizing signal and the vertical synchronizing signal.   
     
     
       19. A video signal processing apparatus according to claim 15, further comprising: extracting means for extracting, from the input video signal, video signal information necessary for the arithmetic operations performed by the arithmetic means, and for supplying the video signal information to the storage means.   
     
     
       20. A video signal processing apparatus according to claim 15, further comprising: timer means for measuring a predetermined period, the predetermined period being an amount of time for the second synchronizing signal to become synchronized with the first synchronizing signal; and wherein   the selecting means selects and outputs the second synchronizing signal as soon as the timer means indicates expiration of the predetermined period.   
     
     
       21. A video signal processing method, comprising the steps of: (a) separating a first synchronizing signal from an input video signal; and   (b) generating a second synchronizing signal; and   (c) selectively outputting one of the first synchronizing signal and the second synchronizing signal as a main synchronizing signal, the first synchronizing signal being selectively output as the main synchronizing signal until the second synchronizing signal becomes synchronized with the first synchronizing signal, and then selectively outputting the second synchronizing signal as the main synchronizing signal.   
     
     
       22. A video signal processing method according to claim 21, wherein the step (b) generates the second synchronizing signal such that the second synchronizing signal has substantially a same cycle as the first synchronizing signal. 
     
     
       23. A video signal processing method according to claim 21, further comprising: (d) measuring a predetermined period, the predetermined period being an amount of time for the second synchronizing signal to become synchronized with the first synchronizing signal; and wherein   the step (c) selects and outputs the second synchronizing signal as soon as the step (c) indicates expiration of the predetermined period.   
     
     
       24. A video signal processing method according to claim 21, further comprising: (d) detecting whether the input video signal is a standard video signal; and wherein   the step (c) selectively outputs one of the first and second synchronizing signals based on output of the step (d).   
     
     
       25. A video signal processing method according to claim 21, wherein the step (c) selectively outputs the first synchronizing signal as the main synchronizing signal when the step (d) detects a non-standard video signal. 
     
     
       26. A video signal processing method according to claim 21, further comprising: (d) storing, in a storage means, the input video signal for a predetermined length of time;   (e) performing arithmetic operations between the input video signal and an output of the step (d);   (f) extracting, from the input video signal, video signal information necessary for the arithmetic operations performed in the step (e); and   (g) supplying output of the step (f) to the storage means.   
     
     
       27. A video signal processing method, comprising the steps of: separating a first synchronizing signal from a current input video signal;   generating a second synchronizing signal; and   obtaining a delayed input video signal based on the first synchronizing signal until the second synchronizing signal becomes synchronized with the first synchronizing signal, and then on the second synchronizing signal.   
     
     
       28. A video signal recording/reproduction apparatus, comprising: synchronizing signal separating means for separating a first synchronizing signal from a current video signal;   synchronizing signal generating means for generating a second synchronizing signal; and   means for obtaining a delayed video signal based on the first synchronizing signal until the second synchronizing signal becomes synchronized with the first synchronizing signal, and then on the second synchronizing signal.   
     
     
       29. A video signal recording/reproduction apparatus, comprising: storage means for storing a video signal for a predetermined length of time;   arithmetic means for performing arithmetic operations between the video signal and an output of the storage means;   synchronizing signal separating means for separating a first synchronizing signal from the video signal;   synchronizing signal generating means for generating a second synchronizing signal; and   control means for controlling operation of the storage means based on the first synchronizing signal until the second synchronizing signal becomes synchronized with the first synchronizing signal, and then on the second synchronizing signal.   
     
     
       30. A video signal processing apparatus according to claim 4, further comprising: means for detecting whether the input video signal is a standard video signal or a non-standard video signal, and controlling the timer means in accordance with the result of the detection.